Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and nutrient enrichment. The goal of this study was to determine how warmer water temperatures and excess nutrients would alter zooplankton communities and phytoplankton concentrations, and whether those changes would...

Climate change has fundamentally altered the water cycle in tropical islands, which is a critical driver of freshwater ecosystems. To examine how changes in streamflow regime have impacted habitat quality for native migratory aquatic species, we present a 50‐year (1967–2016) analysis of hydrologic records in 23 unregulated streams across the five...

The range of the southern sea otter (Enhydra lutris nereis) spans most of the central California coast from Half Moon Bay to Gaviota. Some coastal areas within this range are heavily developed and highly impacted by humans, while other areas are wild and largely pristine. Determining the relative importance of food resource abundance,...

My interests span the coastal zone, from seacliff erosional processes to sediment dynamics in the shallow coastal ocean. My research focuses on the quantitative study of hydrodynamics, sediment transport, and geomorphology in coastal and marine environments.

The U.S. Geological Survey celebrated the 125th anniversary of its national program for topographic mapping (1884–2009). Topographic maps became a signature product of the USGS because the public found them—then and now—to be a versatile tool for viewing our Nation's vast landscape.

Prepared by: Office of Administration, Office of Management Services, Occupational Safety and Health Management BranchDisclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U. S. Government.­­­­Table of Contents...

For general interest, studies and accounts regarding Native American Legends of possible tsunamis in the Pacific Northwest are excerpted below. Much of the information on this page was presented by Jim Bergeron, Oregon Sea Grant, Astoria Extension at a 1995 Meeting in Seaside, Oregon. Those interested in the subject are encouraged to refer to the...

This web page provides files that may be used to run a basic depth-averaged (2DH) Deltares Delft3D version 4.00.01 astronomic tide model for San Francisco Bay. It was developed with the primary aim of assessing water level fluctuations and flow conditions in the vicinity of the Golden...

I study influences of climatic variability and land uses on American drylands—their ecosystems, surface materials, and geologic underpinnings—with emphasis on sediment eroded and deposited by wind, mostly as atmospheric dust. Dust represents local, regional, and global translocation of enormous amounts of matter and energy. I attempt...

Education: B.S. Civil Engineering, University of Missouri - Rolla, 1994Currently, I provide national software support and policy guidance to the Water Mission Area relating to AQUARIUS and other SW related data collection, processing, and publication issues for the Hydrologic Networks Branch. I also teach several training...